Plants respond to herbivore damage with a bewildering array of metabolic responses. To what degree such responses are specific to particular herbivore species and how plants respond to multiple attackers are questions of extensive scientific debate because their answers are fundamental to the understanding of the ecological consequences of plant induced responses to herbivory. In a field experiment, I investigate the nature of secondary metabolite and defensive protein production in Solidago altissima when elicited by two different herbivore species, the larvae of the galling fly Eurosta solidaginis and the chrysomelid beetle Trirhabda virgata, individually or at the same time. The chemical analysis of leaf tissue reveals differential responses in both trypsin proteinase inhibitor production and volatile organic compound emission when goldenrod plants are damaged by either herbivore individually or the two in combination. Our findings suggest damage-specific elicitation and signal transduction for each herbivore individually and for when both attack simultaneously.